My Brand New CTC-7!

[DaveWM]

I would use these

http://www.mouser.com/ProductDetail/...LXo%2fcME9o%3d

I am assuming you are talking about the 160uf 250v doubler caps.

[SwizzyMan]

Originally Posted by DaveWM

I would use these

http://www.mouser.com/ProductDetail/...LXo%2fcME9o%3d

I am assuming you are talking about the 160uf 250v doubler caps.

yup

[rca2000]

Just make SURE whatever you use are EQUAL in value or close to each other..or you will get UNEQUAL voltage across each cap...and a LOT of problems !!

[SwizzyMan]

Originally Posted by DaveWM

I would use these

http://www.mouser.com/ProductDetail/...LXo%2fcME9o%3d

I am assuming you are talking about the 160uf 250v doubler caps.

180uf? The tolerance is that high?

[DaveWM]

yes 180 is a good sub for a 160 when used in power supply doubler.

[rca2000]

A PAIR of 180's will be FINE..just make sure BOTH are 180UF..

[DaveWM]

Originally Posted by rca2000

A PAIR of 180's will be FINE..just make sure BOTH are 180UF..

This is new to me, what kind of issues? I would have assumed that the large variances in caps of the era would have been typical due to tolerances.

[SwizzyMan]

well did It work for your set Dave?

[DaveWM]

yes, never been an issue for me but would like the other poster to chime in, curious as to what problems he has encountered.

the 150uf would work as well, its just I prefer to always go the the NEXT commonly available size that is higher rather than lower. example a 47 for a 50 is fine, but I would generally go with a 56. Again I really don't think it matters, the caps today are so much more accurate that the stuff from back in the day.

IIRC the tolerances were back in the day in the +100 to -50 but that is something I read, and not sure if its correct.

so a 150uf could be 300uf to 75uf. I have seen some mighty odd values used in repairs that worked, but for me I stick with a process, so always go next higher and equal or higher on voltage.

on small caps like 4.7-47uf I typically go way high on voltage, so if a circuit calls for say a 5uf at 50v I will go with a 4.7 or 5.6 but will go much higher on voltage, maybe 160v to 450v. The reason being the size is often a closer fit with the modern caps and I have fewer caps to purchase across a voltage rating. you can use a 450v in a 50v circuit with out issues. Then when you need a 450v 5uf you have it.

[rca2000]

Well,,,I Have SEEN..on MODERN stuff that uses a voltage doubler...if ONE cap in the doubler is bad and off by a signiuficant amount...the output will be very DIRTY. I have SEEN it BLOW OUT--as in physically== caps on the output side--I am guessing it will allow HEAVY ripple or such...

This problem occurred in Samsung DLP sets some years ago--the big cap n the ballast WOULD blow out...if one of the 2 caps used on the doubler...became bad and badly off value.. and the OTHER one was working..

[DaveWM]

I suspect this set which has a rather substantial choke on the output from the doubler would be pretty immune to any big ripple. that being said I agree that it would be good form to go ahead and replace both if one is bad.

one is a single sections that floats above the chassis ground (insulated with a cardboard sleeve, can is NOT grounded. The other doubler cap is part of the 4 section cap that IS grounded.

My guess is the OP has an issue with the grounded can since I doubt he would have noticed the sleeved can getting hot.

Note to OP be VERY careful when working on voltage doubler power supplies re the insulated cap is NOT grounded, rather there is a wire that goes to the can tab, which is NOT twist locked or soldered to the ground. Do this wrong and you will create short, pop a cap, prob a breaker and maybe a diode.

[SwizzyMan]

Originally Posted by DaveWM

I suspect this set which has a rather substantial choke on the output from the doubler would be pretty immune to any big ripple. that being said I agree that it would be good form to go ahead and replace both if one is bad.

one is a single sections that floats above the chassis ground (insulated with a cardboard sleeve, can is NOT grounded. The other doubler cap is part of the 4 section cap that IS grounded.

My guess is the OP has an issue with the grounded can since I doubt he would have noticed the sleeved can getting hot.

Note to OP be VERY careful when working on voltage doubler power supplies re the insulated cap is NOT grounded, rather there is a wire that goes to the can tab, which is NOT twist locked or soldered to the ground. Do this wrong and you will create short, pop a cap, prob a breaker and maybe a diode.

Hmmm I hooked up the eico 950B to that one earlier today to test for leakage did hook the ground to the tab (which I now know is incorrect) ran it at 250v for about 10 seconds then turned it off. I didnt get any shorts I dont think, the chassis powers up fine and I have HV but I have no idea if I would not have a picture since I ran it outside of the cabinet. Hopefully nothing was hurt.

[DaveWM]

when you are testing caps with that tester make sure you have them out of the circuit. I generally unwrap the wire wrap connectors and then unsolder any else like resistors. you dont have to worry about the little disc caps that may be soldered, they are too small to worry about and will not be bad.

if you are going to restuff in place, no need to test just do it, leave the wiring alone (which is the main benefit of stuffing in place).

[SwizzyMan]

Originally Posted by DaveWM

when you are testing caps with that tester make sure you have them out of the circuit.

Ah ok don't think I hurt anything thankfully.

[SwizzyMan]

Alright just bought em' will report back when I get them in.